The present invention relates to a structural element in the front region of a motor vehicle.
Structural elements in the front region of a motor vehicle are well known. They serve for the introduction of load from the front-end section of the motor vehicle into the bulkhead thereof, and are designed for example as front-end section structures and bulkhead structures constructed from sheet-metal shells. Loads of the engine bracket are introduced, by way of a branching of lower longitudinal members and connection members of the front-end structures and bulkhead structures, into the floor structure, the A pillar and the tunnel. Furthermore, structures composed of aluminum are known in which the engine bracket, as a profiled component, transmits its load into the floor and side frame structure via welded-on and riveted-on profiles and cast nodes.
A disadvantage of the known concepts is the limited lightweight construction potential of the metallic materials, and the problems with regard to thermal expansion and corrosion that arise in the case of the combination of metal structures with CFRP structures.
It is therefore an object of the present invention to eliminate the abovementioned problems.
This and other objects are achieved according to the invention by way of a structural element in the front region of a motor vehicle, which structural element is arranged between an engine bracket and a bulkhead of the motor vehicle. The structural element has a deformation element which is fastened by way of a front fixing to the engine bracket and by way of a rear fixing to the bulkhead. The front fixing is connected to the bulkhead by way of an upper shell and a lower shell such that the two shells together form a closed, funnel-shaped structure.
In relation to metallic structural concepts and metal-CFRP mixed structures, the configuration according to the invention yields greater lightweight construction potential. In relation to a purely CFRP shell-type construction, the energy absorption in the event of a crash is considerably increased. The deformation behavior can be controlled in an effective manner through the configuration of the deformation element, and can with little outlay be adapted to different requirements owing to different crash weights in vehicle variants of a type series.
In one advantageous refinement, the deformation element is composed of a fiber-composite plastic.
It is advantageously the case that the rear fixing is connected, in particular screwed, to the bulkhead by way of detachable fastening elements and is supported on load distributor plates which are integrated into the bulkhead.
The bulkhead is advantageously composed of a fiber-composite material with a foamed core.
In a preferred refinement, the load distributor plates are integrated, together with the fastening elements for the rear fixing of the deformation element, into the foamed core of the bulkhead.
The funnel-shaped structure formed by the shells is advantageously connected to the bulkhead such that said structure supports the engine bracket with respect to the bulkhead at least in a horizontal and a vertical direction.
In one advantageous embodiment, the deformation element and the front fixing are fastened to the engine bracket by way of an easily detachable fastening element. Owing to this embodiment, it is possible, in the event of repairs after damage to the engine bracket, for the latter to be exchanged easily and with reasonable outlay.
In order for damage to the deformation element to be easily identified from the outside, it is provided in a preferred refinement that at least one of the two shells is, in at least one sub-region, designed such that, in the event of a load which leads to damage to the deformation element, the shell undergoes visible change.
According to the invention, therefore, the transition from the engine bracket into the bulkhead is designed as a substantially pure CFRP structure. In this case, the stiffness of the front region of the motor vehicle is attained by way of a funnel-shaped structure which produces the connection between the engine bracket and the bulkhead. The crash loads are introduced via the deformation element into the bulkhead, which, in the connecting region, is of sandwich form with an integrated metallic load distributor plate. By way of the combination of the funnel-shaped shell structure with the deformation element situated on the inside, it is possible for all occurring forces and moments to be introduced, in a manner suited to the loads and fiber composite, into the bulkhead which is equipped with a suitable reinforcement.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.